F_VN_GetRoi
Gets the coordinates of the region of interest (ROI) within the image.
Syntax
Definition:
FUNCTION F_VN_GetRoi : HRESULT
VAR_INPUT
ipSrcImage : ITcVnImage;
END_VAR
VAR_IN_OUT
stRoi : TcVnRectangle_UDINT;
END_VAR
VAR_INPUT
hrPrev : HRESULT;
END_VAR
Inputs
|
Name |
Type |
Description |
|---|---|---|
|
ipSrcImage |
Source image | |
|
hrPrev |
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) |
In/Outputs
|
Name |
Type |
Description |
|---|---|---|
|
stRoi |
Returns the coordinates of the region of interest |
Return valueFurther information
The function F_VN_GetRoi indicates which Region Of Interest is currently set on the input image ipSrcImage. The information is required, for example, if points in the image are to be specified in relation to the total image or if the ROI is to be dynamically enlarged.
Application
The referencing of a point to the coordinates of the original image looks like this, for example:
hr := F_VN_ContourCenterOfMass(ipContour, aCenter, hr);
hr := F_VN_GetRoi(ipImageWork, stRoi, hr);
aCenter[0] := aCenter[0] + stRoi.nX;
aCenter[1] := aCenter[1] + stRoi.nY;
Related functions
- F_VN_SetRoi for setting a Region of Interest
- F_VN_GetRoi for retrieving the set Region of Interest
- F_VN_ResetRoi for resetting the Region of Interest on the entire image
- F_VN_CopyImageRegion for copying an image region
Required License
TC3 Vision Base
System Requirements
Development environment | Target platform | PLC libraries to include |
|---|---|---|
TwinCAT V3.1.4024.54 or later | PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU | Tc3_Vision |